1. Field of the Invention
The invention relates to a resilient contact element, more particularly to a resilient contact element that has a durable construction.
2. Description of the Related Art
The resilient contact elements commonly used in the industry are usually made of a bent unitary conductive contact strip, and are mounted fixedly on a surface of a circuit board using known surface-mounting techniques (SMT). By virtue of inherent resilience attributed to the material and construction of the resilient contact elements, the resilient contact elements can be used in electrical connections, grounding, electromagnetic interference (EMI) shielding, etc., between an electric component and the circuit board, or simply as a buffer during contact therebetween.
As shown in FIGS. 1 and 2, a conventional resilient contact element 4 is configured with a mounting section 41, a resilient section 42, and a contact section 43. The mounting section 41 is elongate, and is fixed on a surface of a circuit board 5 using surface-mounting techniques. The resilient section 42 extends from one end of the mounting section 41, and is bent toward the free end of the mounting section 41 to form a semicircular curve. The contact section 43 extends from the other end of the resilient section 42, and is generally parallel to and spaced apart from the mounting section 41. The contact section 43 thus cooperates with the mounting section 41 to form a compressible space therebetween. Accordingly, an electric component, such as an antenna 6, can contact the contact section 43 to establish electrical connection with the circuit boards.
Due to the current trend toward miniaturization of electronic products, the height of the contact section 43 relative to the surface of the circuit board 5 is required to be as small as possible in order to reduce the thickness of electronic products. While the compressible space between the contact section 43 and the mounting section 41 is reduced, the reduction should not be too much in order to maintain the contact capability between the electric component 6 and the contact section 43. Particularly, it is important to ensure that the resilient section 42 can be restored to a proper initial state upon removal of the electric component 6 and that the resilient contact element 4 can be prevented from experiencing permanent deformation. According to actual experiments, for instance, when the thickness of the material of the resilient contact element 4 is 0.08 mm, the smallest curve radius of the resilient section 42 when the resilient contact element 4 is contacted by the electric component 6 is required to be at least five times the thickness of the resilient contact element 4, i.e., 0.4 mm, in order to avoid permanent deformation at the resilient section 42 and eventual damage to the resilient contact element 4. As such, the compressible space between the mounting section 41 and the contact section 43 of the resilient contact element 4 is required to be at least 0.8 mm when the resilient contact element 4 is contacted by the electric component 6 so as to ensure that the resilient section 42 can be restored to the proper initial state.
On the other hand, the distance between the electric component 6 and the circuit board 5 cannot always be precisely controlled to be 0.8 mm. Therefore, on occasions where the distance between the electric component 6 and the circuit board 5 is smaller than 0.8 mm, permanent deformation of the resilient section 42 can occur. Moreover, since the resilient contact element 4 is mounted inside an electronic device, damage to the resilient contact element 4 cannot be detected externally of the electronic device. As a result, poor contact with the electric component 6 at the contact section 43 will be unavoidable in view of the deformed resilient section 42.
It is apparent from the foregoing that the compressible space in the conventional resilient contact element 4 cannot be reduced further due to restrictions imposed by the construction of the contact element 4. Furthermore, when the compressible space is reduced to the lowest permissible limit, the reliability of the resilient contact element 4 is affected adversely.